Effects Of Irrigation Quotas On Growth,Yield And Water Use Of Maize In Yellow River Irrigation Area Of Ningxia

In view of the influence of different irrigation quotas on the growth,yield and water use characteristics of maize in the Yellow River irrigation area of Ningxia,the effects of different irrigation quotas on the growth,yield and water use characteristics of maize in the Yellow River irrigation area of Ningxia were studied with Yinyu 439,Tianci 19 and Lanshan 319 as the tested maize.Exploring the appropriate irrigation quota can significantly improve the yield of maize,and put forward the irrigation system suitable for the main hybrid maize varieties in Ningxia Yellow River irrigation area under the condition of drip irrigation:a total of 8 times irrigation in the whole growth period,1 time irrigation in seedling stage,2 times irrigation in jointing stage,2 times irrigation in bell stage,2 times irrigation in heading stage and 1 time irrigation in filling stage.(1)Before irrigation,the difference of soil moisture content at the same depth and different transverse distances was very significant;the water content at 60cm depth is always high,close to the field capacity.The water content at 20cm depth outside the plant is more practical,and it is also the key part of water demand for maize growth,which should be paid enough attention.So 20cm outside the plant,20cm depth of the site as a suitable point for the determination of soil moisture,drip irrigation amount of lower limit 18.03%,drip irrigation amount of upper limit 22.84%.(2)The plant height,leaf area and dry matter accumulation of maize were the highest under the drip irrigation amount of 3765m3/hm2.There was no significant difference in plant height among Yinyu 439,Tianci 19 and Lanshan 319 under drip irrigation amount of 3765m3/hm2.Under the same drip irrigation amount,the leaf area of Lanshan 319 was larger than that of Tianci 19 and Yinyu 439.There were significant differences in the dry matter accumulation of Yinyu 439,Tianci 19 and Lanshan 319 with drip irrigation amount of 3765m3/hm2 in each period.Only varieties at tasseling stage had significant indigenous effects on chlorophyll content,and varieties at tasseling stage and drip irrigation amount had no significant effects on chlorophyll content(SPAD)of maize leaves.(3)The malondialdehyde(MDA)content and peroxidase(POD)content of Yinyu 439,Tianci 19 and Lanshan 319 were the lowest under the drip irrigation amount of 3765m3/hm2,while the nitrate reductase activity was the highest under the drip irrigation amount of 3765m3/hm2.There was no significant difference in MDA content,POD content and nitrate reductase activity among Yinyu 439,Tianci 19 and Lanshan 319 under different drip irrigation amounts.Therefore,when water supply is insufficient,plant cells will be severely damaged by oxidation.In order to restore normal metabolic capacity,POD protective enzyme activity will rise sharply in varying degrees,and the amount of malondialdehyde is positively correlated with the degree of cell membrane damage.(4)The starch,neutral detergent fiber and acid detergent fiber of Yinyu 439,Tianci 19 and Lanshan 319 under each irrigation quota were the highest under the irrigation quota of 3765m3/hm2.The protein content of Yinyu 439,Tianci 19 and Lanshan 319 was the lowest under the irrigation quota of 3765m3/hm2.Under the same irrigation quota,the protein and acid detergent fiber contents of Lanshan 319 were the highest,and the starch and neutral detergent fiber contents of Yinyu 439 were the highest.However,there was no significant difference in protein,starch,neutral detergent fiber and acid detergent fiber among Yinyu 439,Tianci 19 and Lanshan 319 under different irrigation quotas.(5)The highest yield of Yinyu 439,Tianci 19 and Lanshan 319 were 16421.51kg/hm2,17518.83 kg/hm2 and 18249.31 kg/hm2 under drip irrigation of 3765m3/hm2.Drip irrigation amount of 3765m3/hm2 can improve maize growth physiology,resistance to adversity characteristics and nutritional quality,but also can increase maize yield,water use efficiency is improved.At the irrigation quota of 3765m3/hm2,the water consumption during seedling emergence and jointing stage was 41.2 mm,and the cumulative water consumption was 41.2mm;water consumption in jointing-tasseling stage was 147.2mm,and cumulative water consumption was 188.4mm;the water consumption during tasseling-filling stage was 85.8mm,and the cumulative water consumption was 274.2mm.The water consumption at the stage of grouting-maturity was 62.9mm,and the cumulative water consumption was 337.2mm;the water consumption at maturity stage was 39.1mm,and the cumulative water consumption was 376.3mm.